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In April of 2009, third-generation black (BS3), red (RS3), yellow (YS3), and white (WS3) colored stocks of pearl oyster Pinctada martensii were compared in terms of fertilization, hatching, survival, and growth. Among stocks, there were no significant differences in fertilization rate (P > 0.05; values ranging from 94.8%–98.9%). Hatching rates of WS3 were significantly lower (P 0.05). At days 15, 23, 90, 150, 210, and 325, however, significant differences in mean shell length among the four colored stocks were observed (P < 0.05). The BS3 stock had consistently larger mean shell length than the other colored stocks.

In this paper, the LEGO mobile robot separating the main body and the peripheral task kits is successfully constructed using by the 3D modeling software and by the hierarchical design method from top to bottom, with LEGO mechanical hardware as body, Lego servo motor as actuator, Lego color sensors as the detection device, Lego EV3 as main controller. The hardware performances of the LEGO mobile robot are tested with matching tasks using the EV 3 oscilloscope platform. The LEGO mobile robot is successfully controlled using by designed algorithms and LEGO Mindstorms EV 3 software platform according to FLL game rules and related tasks. At the same time, all tasks of the robot are accurately completed by regulating the path identification, the error compensation, precision control in the overall design process.

The assimilation properties of iron ores are important during sintering. The amount of formed calcium ferrite was firstly used to evaluate the assimilation. Then, temperature and time of assimilation were proposed rather than the former one, which simplify the process and improve the operahility of experiments. However, the factors affecting the temperature were always neglected and using several indexes to evaluate the assimilation was inconvenient. In this paper, the assimilation reaction characteristic number taking the actual sintering temperature as the reference temperature was put forward to evaluate the assimilation of iron ores. This assimilation reaction characteristic number was a dimensionless number including kinds of important information during the assimilation reaction process. Results showed that the assimilation characteristic number can reflect the overall process of assimilation reaction between ores and CaO, which could help further analyze the assimilation difference of ores.

Under the Federal Milk Marketing Order (FMMO) and California milk pricing systems, minimum milk values are determined by the value of components important in dairy product manufacturing. This implies that milk values will vary across farms due to different solids composition (fat, protein and other solids) delivering to the same processing plant. Milk composition can be managed by farm operators by a number of management activities such as: breed choice, number of lactations to keep a cow in the milking herd, ration formulations, feeding management, whether to milk 2 or 3 times daily, and cow comfort. Given the milk pricing systems used for a majority of raw milk in the U.S., dairy farm operators are faced with an environment of maximize profits via a multi-output production function, (i.e., production of milk components). Previous analysis of dairy farm efficiency has typically used the total amount of milk produced (cwt of lbs) as a measure of output, not the production of its components. In this paper, we use hedonic aggregation functions to generate output indices in the evaluation of an input-oriented distance function. We use data from the 2005 USDA Agricultural Resource Management Survey (ARMS)-Dairy Survey for this analysis. A unique feature of the 2005 survey is that it contains information on the annual amount of milkfat and protein produced by the milking herd. From this analysis we find that the estimated technical efficiency when using component amounts as output measures has less variance, but larger range, compared to the method using milk yield as output. A majority of dairy operations generate technical efficiency measures of more than 9.0 (with 1.00 being the possible maximum.

The pearl oyster Pinctada martensii is an important economic shellfish species and mainly cultured in the southern provinces of China. The species is cultured for marine pearl production. However, pearl quality has recently decreased because the cultured stocks had slow growth and mass mortalities caused by inbreeding depression. We have initiated a selective breeding program to improve the cultivated stocks since 2002. In 2004, a base population was developed by collecting the breeders from Beibuwan and Liushagang stocks. During the period of 2005–2007, a two successive generation selection for shell length in the base population was carried out to produce the second generation selected and unselected lines. In May of 2008, three types of lines were produced by selecting the breeders from the second generation selected and unselected lines. The three types of lines were designated as SS (Selected for three generations), SC (selected for the two generations) and CC (unselected for three generations). Realized heritability for the third generation, cumulative (over three generation) and current (for the third generation) genetic gains were evaluated by comparing the growth performance of three types of lines at days 8, 16, 45, 75, 180 and 360. It was found that the SS lines had significant larger mean shell length and shell height than the SC and CC lines at all sampling ages (P

The impact-corrosion-abrasion resistance of the low carbon high alloy steel, which can be used for mill lining under impact-corrosion-abrasion condition, are tested in laboratory by means of a new kind of experimental facility. The industrial trial run in the same condition has also been completed. The results show that the new alloy containing 0.2 wt.% carbon, 9 wt.% chromium, and 2 wt.% nickel is consisted of lath martensite entirely, and is more than two times superior to Mn13 cast steel in impact-corrosion-abrasion resistance. Spelling is the leading wear mechanism in impact-corrosion-abrasion condition for this alloy, which is lighter than that of high manganese steels because of its better hardness-toughness match.

The impact corrosion-abrasion properties and mechanism of high manganese steel were investigated under different impact energies. The result shows that the wearability of the steel decreases with the increase of the impact energy. The dominant failure mechanism at a lower impact energy is the rupture of extrusion edge along root and a slight shallow-layer spalling. It transforms to shallow-layer fatigue flaking along with serious corrosion-abrasion when the impact energy is increased, and finally changes to bulk flaking of hardened layer caused by deep work-hardening and heavy corrosion-abrasion.

The Conservation Reserve Program (CRP), which provides financial incentives for landowners to idle erodible and marginal farmland, has contributed to a number of environmental benefits that otherwise would have not been achieved. However in the last few years CRP faced a number of new challenges as record-high crop prices significantly affected landowners’ interests to participate in the program. Despite an extensive literature on CRP, we lack evidence on how landowners react to changes in agricultural market conditions and CRP payment rates and hence how it affects the program enrollment and cost. In this paper, we attempt to investigate landowners’ incentives for CRP participation focusing on the linkage between farmers’ CRP payment bids and unobserved agricultural productivity. We develop and estimate an empirical structural model to examine the manner in which agricultural productivity, market conditions, and CRP payment affect landowners’ land use decisions. A novel identification strategy is employed to control for endogeneity and self-selection. The parameter estimates are used to simulate how changes in agricultural prices and CRP payment influence the program enrollment and cost.

In final approach of rendezvous between a space robot and a non-cooperative target, due to the light and the folds of heat cladding materials on the target surface, the edge of target cannot be accurately extracted by classic Canny algorithm and we are unable to complete measurement of relative position and attitude. To solve this problem, the measurement method of relative position and attitude between two non-cooperative spacecrafts based on graph cut and edge information algorithm is proposed. A circular feature of the target is chosen as the recognition and measurement object. Firstly, the edge of the circular feature on the target is accurately extracted by graph cut and edge information algorithm. Secondly, the edges are ellipse fitting. Lastly, the relative position and attitude of target is obtained by fitting ellipse parameters of binocular cameras. The simulation results show that the precision of this method is better than Canny algorithm's and it can better meet the mission requirements.